Making Savings with Smart Technology

The use of efficient asset management technology together with smart valves provides significant benefits by avoiding unexpected shutdowns and when planning maintenance actions.

By Ismo Niemelä, Director, Neles Smart Products, Metso’s Automation business

Making savings with smart technology
Most companies in the process industry understand that the cost of buying field equipment is only the beginning. The lion’s share of lifetime costs relates to lifecycle phases, such as installation, commissioning, operation and maintenance. The same is true of process valves.

Lifecycle costs are also heavily influenced by the choice of process valves and of maintenance strategy. Purchase price differences between equipment manufacturers can be outweighed by costs arising during the later stages of service life. However, TCO reductions can be achieved during all lifecycle phases by using the latest technology and intelligent valve controllers,

Cutting installation costs
When a device is installed, wiring, the number of additional instrumentation components and of outputs must be considered. Fieldbus technology, which aims to reduce wiring costs, is available for control valves using FOUNDATION fieldbus or Profibus PA. Several bus solutions are available with on/off valve applications, such as As-i, DeviceNet, Modbus or FOUNDATION fieldbus could be used in many applications.

The number of instrumentation components affects not only purchase cost; but also maintenance concerns, being a potential leakage source for instrument air. The more components, the more the potential sources of failure and hence additional reliability concerns.

There is a solution on the market with a high pneumatic capacity, which provides fast action when needed and the possibility to control instrument airflow to provide slower action. This controller also provides profile opening and closing. With this device, limit switches can be integrated for greater compactness and reliability. This eases installation and makes it cost efficient. Such an integrated package also simplifies the purchasing process. Fig. 1 shows the traditional solution on the left and the new one on the right.

With emergency shutdown (ESD) valves, end-users now pay increasing attention to safety, where improvements are offered by testing more frequently using instrumented partial-stroke testing. The PST test device can perform both partial-stroke testing and the safety function, which eliminates the need for an additional solenoid valve. Even more importantly, these devices test not only the ESD valve but also its pneumatics, resulting in greater reliability and increased safety.

Another cost benefit is that the new solution operates with one output from the safety system. While In a traditional solution, the positioner needs an analogue output for the PST function and the solenoid valve needs a digital output for the safety function. Naturally this new solution has high pneumatic capacity and integrated limit switches, which further reduce installation costs.

Figure 2 shows an ESD valve with the new intelligent valve controller. Customers report savings such as: “At least 25% less assemblies with extra instrumentation components and half of those required safety locking”.

Commissioning and start-up
During commissioning and start-up there is substantial savings potential. One of the first actions is to verify cable connections and installation progress. With smart devices and an asset management system capable of scanning the whole device network, it is easy to monitor the progress of the physical installation and connections to the automation system. During commissioning it may be necessary to configure, calibrate and fine-tune a valve by means of local push buttons and a keypad or by a PC and asset management system.

During start-up, a quick trouble-shooting capability may be needed. Devices that recognize sudden problems immediately by using an asset management system can provide significant time saving and enable faster start-up.

Operation

During normal operations, a control valve keeps process variables as close as possible to the setpoint. Using an intelligent valve controller on a control valve helps to achieve minimum process variability. Employing the right technology using sensors and an intelligent control algorithm enables any control valve to follow the control signal quickly and accurately. Figure 3 shows a control valve with an intelligent valve controller.


Control valve sizing and selection are based on information, such as the type of medium, flow rate, pressures before and after the valve, flow-medium temperature and pipe diameter. Sometimes actual conditions deviate from design conditions and frequently a smaller valve or trim would suffice. Oversized valves can lead to poor process control and increased process variability. With undersized valves, lower flow capacity results in production output will be limited. Intelligent valve controllers can expose over- or undersized valves. Figure 4 shows how a valve position histogram is collected and is shown using a DTM.

With ESD valves, although safety is the principal criterion, potential TCO savings also exist. Reliability and safety should be improved by testing valves during normal operation to ensure they can operate in an emergency. Nowadays, manual testing is used less and less; tests are made remotely with intelligent valve controllers performing so-called partial-stroke tests (PST). This reduces TCO during operation and increases safety, because the test can be made automatically and as often as required to maintain the required SIL level.

With all automated process valves, TCO savings during operation exist thanks to intelligent valve controllers, their diagnostic capabilities and the possibility of warning of potential valve problems that can result in loss of production. Figure 5 illustrates the system: intelligent valve controllers diagnose valve condition. When the valves are connected to an asset management system that automatically checks the device, any status change can be passed to anyone in charge of process plant management.

Up to 30% TCO savings over a valve’s lifecycle
New technology and intelligent valve controllers provide excellent tools for achieving savings with both control and ESD valves as well as with automated on/off valves. Because intelligent valve controllers can diagnose valves, they enable the development of predictive maintenance at process plants. Intelligent valve controllers can provide huge benefits when planning maintenance shutdowns and they help to determine which valves really need maintenance.

Intelligent valve controllers offer many ways of reducing the total cost of ownership of valves in process control and automation. Originally used with control valves, nowadays, all automated process valves can be provided with intelligent valve controllers. Thus TCO savings can be achieved with all automated process valves.
The degree of TCO savings depends on how fully and in which lifecycle phase/s beneficial features of new technology are utilized. Remarkable savings can be achieved in any lifecycle phase because the initial investment can represent as little as 20% of total lifetime costs. When the TCO saving potential of intelligent valve controllers is utilized to the full in all life cycle phases, actual savings can reach 30% or more during the whole lifecycle.
Ismo Niemelä,
Director, Neles Smart Products

Metso Automation Ltd, Tel: 0870 606 1478
www.metso.com

Reprinted with the permission of Hydrocarbon Engineering magazine. The complete article has been published in Hydrocarbon Engineering July 2010 issue.

Published in Valve User Magazine Issue 15


Winter 2019 // Issue 51
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